Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

It was another dreary day on Wall Street and for the S&P 500 , with mounting fears of slower growth beginning to get into the minds of investors who pushed the iconic index to its third straight loss.

At the heart of today's worries was new homes sales data that showed a 7% drop in December for a seasonally adjusted sales rate of 414,000, well below economists' expectations. This rapid fall in new home sales could put a damper on the entire housing sector and also points to just how fickle consumers and prospective homebuyers have been with regard to interest rates. Having been spoiled by record-low lending rates for years, consumers are simply sitting on their hands and waiting for even lower rates rather than jumping at the opportunity to buy a home at near record-low rates.

In addition, corporate earnings from the fourth quarter haven't exactly lit a fire under Wall Street. The initial indications would suggest that top-line growth is sluggish, and more companies than normal have actually come forward and lowered their quarterly or upcoming full-year expectations. I've contended (incorrectly thus far, may I add) for some time now that share buybacks and cost-cutting are masking sluggish corporate growth, and investors just might be waking up to that fact this earnings season.

By day's end the S&P 500 ended lower by 8.73 points (-0.49%), to close at 1,781.56, bringing its three-day loss total to 3.43%.

Bucking the trend, however, and leading the charge to the upside was small-cap clinical-stage biopharmaceutical company Oramed Pharmaceuticals which advanced 21.9% after saying it will announce Thursday the results from its phase 2a clinical trial for oral insulin treatment ORMD-0801 for type 2 diabetes. Shares of Oramed have been on fire since December, after the company announced positive results from a phase 1 pharmacokinetic study of ORMD-0801 in type 1 diabetes. Investors have since then been eager to see if these solid results translate to a wider population, since 90% of all diabetes cases are type 2. However, with shares having quadrupled in a month and the company wholly clinical-stage in nature, long-term investors may want to back off and let Oramed report its results later this week before making an investment decision one way or the other.

Mobile advertising platform operator Millennial Media roared higher by 9.7% after announcing its preliminary revenue and EBITDA guidance for the fourth quarter. Millennial said in a press release it now anticipates reporting revenue of $106 million-$109 million with pro forma combined adjusted EBITDA of $5 million-$6 million. This compares favorably against Millennial Media's previous quarterly guidance of $95 million-$100 million in revenue and breakeven-$2 million in pro forma combined adjusted EBITDA. Millennial has worked hard at reducing costs while also expanding its business and looking for new avenues of growth. It's clear that a good chunk of mobile advertising growth is still up for grabs, but the question is whether those opportunities will prove consistent enough over the near term for investors to rally behind Millennial Media.

Finally, Xoom , a company that supports consumer-to-consumer online and mobile money transfers, jumped 9.1% after today announcing that it had launched a new series of ads touting its mobile transfer convenience to the Hispanic community. While many of us might take our ability to obtain cash for granted, large numbers of people around the world still have little to no access to a bank. Therefore, Xoom's ability to enable consumers to transfer money at the click of a button offers plenty of next-generation promise. At 72 times forward earnings Xoom might be a bit pricey, but with a growth rate well in excess of 20% it definitely deserves a premium over other financial service providers. It's a company I'd suggest adding to your watchlist.

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